Abstract

Marine mammals are considered sentinels for aquatic ecosystem and human health because of their long lifespan, long-term coastal residency, potential to serve as depots for toxins, and charismatic power. The Florida manatee (Trichechus manatus latirostris) is an endangered marine mammal that has been the subject of numerous conservation efforts over the years. Major population threats such as watercraft trauma and loss of warm-water habitat have received significant attention; however, recurring unusual and mass mortality events and continuing habitat and environmental pressures increase the need for an interdisciplinary approach to research and conservation efforts. Historically, red tide blooms in southwest Florida have made a significant impact on manatee-, human-, and ecosystem health. More recently, Florida Fish and Wildlife Conservation Commission (FWC) researchers and partners have responded to elevated mortalities of manatees, brown pelicans, and bottlenose dolphins in the Indian River Lagoon (IRL). These mortalities followed a dramatic reduction of seagrass in the area due to long-term, non-toxic phytoplankton blooms. Manatee deaths in the IRL reached catastrophic numbers by late winter of 2013 when an Unusual Mortality Event (UME) was declared. To date, the investigation into the yet-unknown cause of these multispecies mortality events and any possible relation with the environmental changes is ongoing. These UMEs and other emerging threats that have been identified by FWC’s manatee necropsy program and organized health assessments, some of which have possible zoonotic potential (e.g., bacterial species, Toxoplasma gondii), highlight the importance of multidisciplinary investigations following the One Health concept.